The invention relates to liquid dispensing apparatus such as watering devices for providing drinking water for birds, small mammals, dogs, cats, chickens, plants and the like. Numerous other applications will be apparent to those skilled in the art. Although the description will be described in terms of water dispensing apparatus, it will be understood to also have application to dispensing of other liquids.
The prior art includes a number of devices using a single conduit extending from a reservoir to a location where the liquid is used. Such devices are shown in U.S. Pat. Nos. 4,148,155; 180,242; 1,564,350; 662,990; 516,637; 294,932; 198,744; 975,607; 1,059,142; 1,042,240; 4,192,256; and 614,238.
Such devices have not been wholly satisfactory, in part, because they are not reliable. Other devices tend to be expensive, bulky, hard to clean, adjust and repair as well as limited in size, shape, and volume. Some have a high evaporation rate and therefore the water supply does not last long. Known devices with a water seal to close off continuing flow require the air flow which replaces the displaced water to travel through the same fluid conduit opening as the water flow, but in the opposite direction. This rarely works well on small watering devices because surface tension prevents water flow. A further problem with this opposite flow is that any surface contaminates tend to enter the reservoir.
It is an object of the invention to provide simple, reliable apparatus for dispensing a liquid.
It is another object of the invention to provide apparatus which is very inexpensive to manufacture.